Dry ice usage question

Question for those of you using dry ice, not counting vapor recovery how much dry ice does it take to prechill both the butane solvent and material column to Neg 48 Deg C(in practice)? Looking at numbers from others they seem to be using 1lb of dry ice per lb of biomass to be processed, does this sound like a reasonable number?

I have 2 50 lb tanks, 2 6 inch by 36 material columns, and 2 6 inch by 36 inch dewaxing columns. The material columns are on a chiller but the dewaxing columns and recovery tanks are dry ice.

I buy 100 lbs of dry ice and use about 25 percent before I start the run. So about 2.5 lbs per lb of material. That varies tho depending on the container your tanks are in and how much I can fit in a columns. Some times I can only fit 4.5 lbs in a column, sometimes I can fit 6 lbs depending on the material. You are not gonna find an exact ratio.

At the end of my run I usually have about 10 lbs of dry ice left. Sometimes less.

I’m doing something wrong man i blow through ice 100lbs gets me 3 or 4 1lb runs.

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Do you CRC?

I’ve been using about 75-100lb per run with my 6x48 column and 50lb solvent tank.

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I recently started using isopropyl kept in -30 freezer, so its pre chilled. lots of it,
fill my vessels 2/3 iso and the other 1/3 dry ice, topping off dry ice as needed and hence using a lot less dry ice, this is #25 lb recovery tank, 2 coils, dewaxer.
And i reuse the iso a few times, my fluke ir gun goes to -50f, it faults out

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Something I do to minimize dry ice usage is to prechill my solvent tank in a freezer. I consume much less dry ice initially this way…starting at -10f out of the freezer and I’m already half way there.

I just bought, but have yet to use, an injection coil, to also try and minimize my dryice usage. I will now take my tank at -10 from the freezer, and run it through an injection coil that lives in a dry ice slurry. I imagine I will use less dry ice to as the coil will be way more efficient at cooling the tane…

Are you using the bulk of your dry ice during recovery or to chill preinjected solvent?

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I’m building a solvent pre-chiller with a used SS keg and modified minifreezer (same idea as diy kegarator).

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recovery in dry ice/alcohol (6 x 12 in 5 gal bucket), material sleeve (3 x 24) filled and usually the remainder of the slurry used for recovery is enough to chill solvent tank. I keep my butane in the freezer before i blast as well. I do soak for an hour+ overall but usually i don’t even top off dry ice.

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Prob dont need a slurry. Do you use a recovery coil?

Do u blow thru ice or dry ice? I used ice on a small machine when I first started and i went thru as much as you. When i upgraded dry ice was necessary.

Also are you recovering 3 or 4 seperate times?

Yes. My crcs are unchilled but freeze over because the solvent is so cold. My end product is really nice so I dont feel the need to cool the crc.

IPA or acetone plus dry ice gets you -78°C. The solvents slow down the sublimation of the dry ice.

@Slabby no coil that’s part of the next upgrade.

@Anonymousextract yeah collection is too small to batch multiple runs so recovering each run.

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A recovery coil would help alot. Usingbthe tank as a condesor works but not as effecient.
Keeping your tank covered in dry ice is alot harder then a coil

@Slabby Ditching the master cool for a built tank is a future upgrade I’m just struggling on finalizing the design I want to use before i start buying parts and then regret sets in. Would a coil in a slurry be sufficient to get a jacketed de-waxing column cold enough to be effective? If so is there a formula for sizing ft of coil to pump flow vs the size of column? I’ve searched around here and not seen much talk about it. Chillers as you know cost as much as another system so it’s out of the budget right for now. if not sleeved de-waxing and struggling to fill it is in my future as LN isn’t a option for me right now.

I’ve been using the same denatured alcohol since last March when I accidentally died it green! I just keep adding to it and put the lid on it when I’m done. If you add fresh to it seems to work great for me

OP
I cool 3gal(halfway up 6x12 tank/ collection in 10gal round cooler)roughly denatured for collection and recovery all in same cooler. I take about 30lbs to really get it cranked up for the first lb. Every lb after that since the alcohol is cold already only takes about 10-15lbs more each lb after. I’ve did 4-5 runs on 80lbs. Even quit that night and restart the next day. I could use less but I buy it Friday to run Saturday and Sunday so I can take my time

Having a small tank really help if u run small 1lb runs. Having the ability to use the same cooling vessel for everything make it nice if your doing it this way

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Same collection here, sometimes I’ll add another 6x12 gets me 6x28 roughly, works for 2lb runs or multiple 1lb , if i have same strain, Gatorade cooler, tank is in giant soup pot, 25lb tank, i leave that iced even for days straight, i was entirely spending way too much on dry ice, but i hated running low, i would add iso to fill, i switched last time, got way more iso, pre chilled -30f or so, 2/3 to 1/3 dry ice, i know liquid ha way better thermal properties, and yes, easier to deal with, drain instead of getting to get ice out of jackets, and back to the gallons, i even filter it, lol. More cost effective, just better all around

Giant fucking run on… :grin: